Managing Serviceguard Eighteenth Edition, September 2010

where the package is running and monitoring the health of all interfaces, switching
them when necessary.
NOTE: Serviceguard monitors the health of the network interfaces (NICs) and can
monitor the IP level (layer 3) network.
Stationary and Relocatable IP Addresses
Each node (host system) should have at least one IP address for each active network
interface. This address, known as a stationary IP address, is configured in the node's
/etc/rc.config.d/netconf file or in the node’s
/etc/rc.config.d/netconf-ipv6 file. A stationary IP address is not transferable
to another node, but may be transferable to a standby LAN interface card. The stationary
IP address is not associated with packages. Stationary IP addresses are used to transmit
heartbeat messages (described earlier in the section “How the Cluster Manager Works”)
and other data.
IMPORTANT: Every subnet configured as a monitored_subnet in a package configuration
file must be configured into the cluster via NETWORK_INTERFACE and either
STATIONARY_IP or HEARTBEAT_IP in the cluster configuration file. See “Cluster
Configuration Parameters ” (page 143) and “Package Parameter Explanations” (page 287)
for more information.
In addition to the stationary IP address, you normally assign one or more unique IP
addresses to each failover package. The package IP address is assigned to the primary
LAN interface card by the cmmodnet command in the package control script when
the package starts up.
The IP addresses associated with a package are called relocatable IP addresses (also
known as package IP addresses or floating IP addresses) because the addresses can
actually move from one cluster node to another on the same subnet. You can use up
to 200 relocatable IP addresses in a cluster. These addresses can be IPv4, IPv6, or a
combination of both address families.
Because system multi-node and multi-node packages do not fail over, they do not have
relocatable IP address.
A relocatable IP address is like a virtual host IP address that is assigned to a package.
HP recommends that you configure names for each package through DNS (Domain
Name Service). A program can then use the package’s name like a host name as the
input to gethostbyname, which will return the package's relocatable IP address.
Both stationary IP addresses, and relocatable IP addresses on subnets that are configured
into the cluster, will switch to a standby LAN interface in the event of a LAN card
failure.
90 Understanding Serviceguard Software Components